Adjustable step-up box for exercise



FIG. 1 is a perspective view of an adjustable step-up box for exercise showing my new design;

FIG. 2 is a left side elevational view, the right side being a mirror image;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for an adjustable step-up box for exercise, as shown and described. 